Telephone system



Feb. 26, 1924.; 1,484,933

, R- D. CONWAY TELEPHONE ,YsTEM Filed Dec. :29 1919 6 Sheets-Sheet 1 TELEPHONE SYSTEM Filed bee. 29. 1919 e Sheets-Sheet z ila Wye/77w; Roy .0. C0/7Wdj Feb. 26, 1924; 1,484,933 R. D. CONWAY TELEPHONE SYSTEM Filed Dec. 29 1919 6 Sheets-Sheet 5 Feb. 26, 1924; 1,484,933

R. D. CONWAY TELEPHONE SYS TEM Filed Dec. 29, 1919 6 Sheets-Sheet 4 rin . //7ve/ 7f0/ Roy 0. Conway.

Feb. 26,1924. 1,484,933

R. D. CONWAY TELEPHONE SYSTEM Filed Dec. 29, 1919 6 Sheets-Shae; '5-

R. D. CONWAY TELEPHONE SYSTEM 7 Filed Dec. 29 1919 6 Sheets-Sheet 6 Patented Feb. 26, .1924.

no; 19. CONWAY, or CHATHAM, NEW JERSEY, Assreuon ro wns rEnn n Ecrn-ro com- PANY, INCORPORATED, 01? NEW roan, n. 1 a conroaa'rron or NEW YORK.

'rnnsrnons SYSTEM.

Application filed. December 29, 1919. Serial No. 348,123.

To 0Z5 Whom. if may concern:

Be it known that I, ROY D. CONWAY, a citizen of the United States, residing at Chatham, in the county of Morris, State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, conelse, and exact description.

This invention relates to alrimproved method and means for signaling over transmission lines and has particular reference to such method and means as applied to telephone systems.

Toll signaling systems have been devised wherein physical and phantom lines are employed for connecting distant oifices or subscribers; In such systems, certain of the lines are employedfor the transmission of various signals utilized to signal operators at distance ollices and to control the operation of telephone repeaters at intermediate ofiices. This has been accomplished by the transmission of a single impulse upon the insertion oi the plug of a link circuit into the jack of any line when initiating a call.

An object of the invention is to transmit a series of. impulses to operate telephone repeaters associated with transmission lines when a change in condition occurs on any one of said lines, and to then transmit another series of impulses in response to another change in condition of said line to identify the line.

Another object is to identify any one of a flurality of transmission lines by the transmission of a series of impulses over a signaling circuit common to said lines and connected to certain of them. The means for accomplishing this object preferahly comprises an impulse mechanism including a plurality of groups of relays common to the transmission lines, and another group of relays cooperating with the first named groups to transmit a series of successive impulses. each relay of the other group being individual to one of saidlines.

For a complete understanding of the invention, reference is made to the accompanying drawings in which Figs. 1 to 6 inclusive, illustrate diagrammatically a preferred embodiment of the invention; and Fig. 7 is a diagrammatic view illustrating the manner in which Figs. 1 to 6 are to be arranged and also showing a; link circuit at each terminating end of the'main circuit.

Briefly, the invention is shown as consisting of two distant offices X and Z and an intermediate otfice Y with ph sical lines A and C and a phantom line interconnecting said othces. Each terminating or distant ohice has associated therewith, an impulse sending mechanism which is operable upon the insertion of a plug into a jack at the office to transmit a series of impulses over a common signaling circuit including conductors simplexed to the physical lines A and C. In the present instance, each series consists of five impulses, four of which are of one polarity and the remaining one of a different polarity. lVhen, for example, a call is initiated 011 any one of the lines at office X. the impulse relay 4'? is energized in order that the impulse of a different polarity may be transmitted fourth in the order of succession of the impulses of the series. This fourth impulse is utilized to render effective the telephone repeaters RA, RB, and RC associated with the lines A, B and C at the intermediate office 1. If the line A at otfice X is taken for use. the impulse relay 17 associated therewith will be energized as soon as the operator actuates the ringing key 3 ot a link circuit D, which is connected to jack 10. The operation of this ringing key also initiates a second series of five impulses, ifour of which are of the same polarity and the remaining one of a different polarity as in the case with the first series of impulses. However, in the second series, the order of sequence is different in that the first impulse. instead of the fourth is the one of different polarity. At ofiice Z mechanism is provided which is responsive to the secondyseries of impulses and this mechanism includes a rela individual to each of the lineswhich is operated when ringing current is transmitted over that line by the actuation ot the ringing key 3 of the link circuit connected thereto. In the case assumed, where the call is initiated over line A, and the relay 17 is operated by the actuation of the ringing key. the relay 212 individual to the line A at otfice Z is operated to effect the display of a signal at the operators position so that the particular line over which the call is initiated is indicated thereat. As long as any one of the lines is in use, the telephone repeaters at the intermediate ofiice will remain effective, but upon the withdrawal of the plugs of the linkcircuits .E at office Z It is believed that the invention will now be full understood from the following detailed description of the operation when considered in connection With the foregoing description.

X ac'tiatcs a call over Zine Operator at ofiice car-0M2? A.

The operator at ollice X desiring to communicate with the operator at oiiice Z over the line circuit A, inserts plug 1 of a link circuit D at office X into jack 10 of line circuit A. Relays 67 and 2 thereupon operate over a circuit traceable from battery through the Winding of relay 2, the sleeve contacts of plug 1 and jack 10 and the wind ing of relay 67 to ground. In response to theoperation of relay 67, relays 68 and 69 operate over an obvious circuit but relay 69 is slow to operate and release. being indicated as such by the arrows intersecting its armature and pointing in the direction that the armature is slow to move, so that during the interval after relay 68 is operated and PIlOl to the complete operation otrelay 69, relay l? is operated over a circuit eX- tending from battery through the alternate contact of relay 68, the upper winding of relay 47 and the normal contact of relay 69 to ground. Relay l? is thereupon locked and relay 62 is operated over a circuit extending from battery through the right hand normal contact of relay 65, the winding of relay 62, .the right-hand normal contact of relay 45, the left-hand normal contact of rela 46 the middle alternate con tact, the lower winding and upper alternate contact of relay 47 to ground.

The closure of the contact of relay 62 completes the circuit extending from battery through the right-hand normal contact of relay 65 to junction point 58, where it divides one branch of the circuit extending from the junction point through the winding and normal contact oit'relay 6 1, and the contact of relay 62 through the interrupter 63 to ground. Relay 64 operates when the circuitis closed through the interrupter 63 and locks over a circuit extending from battery through the right-hand normal contact of relay 65,- junction point 58, winding and left-hand,alternate contact of relay 6% toground. Thereupon a circuit is completed When a live segment of interrupter 66 is reached'which extends from battery through relay 73, the lower normal contact of relay 1.7, the junction point 18, the left-hand normal contact of relav 15, the right-hand alternate contact of relay 64, the left-hand normal contact of relay 65 and the interleft-hand normal contact of relay 15,

rupter 66 to ground. By the operation of rclay 73 the selecting battery 59 is connected across the signaling path. such operation will be described later. Helayj16 operates over a circuit extending from battery through the right-handnormal. contact of relay 65, the unction point .58, the winding otrelay 16, juuctioi point 18, the the right-hand alternate contact of relay 6 1, the left-hand normal contact 01" relay 65 and the interrupter 66 to ground. Relay 15 thereupon operates over a circuit extending from battery through the right-hand normal contact of relay 65, junction point 58, the middle alternate contact of relay 16, the middle normal contact ott' relay 15 and the winding of relay 15 to ground. Relay 15 in operating locks over a circuit extending from battery through the right-hand normal Contact of relay 65, the junction point 58, the right-hand: alternate contact and Winding of relay 15 to ground. By the opening of the left-hand normal contact of relay 15,, relay 73 is released, independently of the interrupter 66. l Vhen relay 15 is energized, alocking circuit is established for relay 16 extending from battery, the right-hand normal contact ot'relay 65, the Winding and right-hand alternate contact of relay 16, the left-hand alternate contact of relay 15, the right-hand alternate contact of relay 6 1, the left-hand normal contact of relay 65 and interrupter 66 to ground. This circuit is opened and relay 16 releases when interrupter 66 reaches a non-grounded or dead segment.

Relay 78 again operates when interrupter 66 engages a grounded segment over a circuit extending from battery through the right hand. normal contact of relay 65, junction point 58, winding of relay 73, the lower normal contact of relay 2?, the left-hand normal contact of .relay 25, the rightdiand normal contact of relay 16, the lett-lunul alternate contact of relay '15, theright hand alternate contact oi relav 64, the left-hand normal contact of relay 65 and the interrupter 66 to ground. Relay'26 also operates over a circuit extending from. battery through the right-hand nonnal contact of relay 65, junc- 58, the middle alternate contact of relay 26.

the middle normal contact of relay and the Winding of relay to ground. Relay 25 in operating locks over a circuit extending from battery through the right-hand normal contact of relay '65, the junction point 58 and the right-hand alternate contact and Wind- The resin it of V hand i ,as leee ing of relay 25 to groun l. Energization t relay establishes a locking circuit for relay 26 extending from grounded battery right-hand normal contact ofv relay 65, unction point 58, the Winding and right-hand alternate contact of rela 2 l tt-hand alternate contact of relay 25, right-hand normal contact of relay 16, left-hand alternate contact of relay l5, right-hand contact alternate of relay 64, left-hand normal contact of relay 65 and the interrupter 66 to ground. This circuit is maintained until the interrupter reaches a non-grounded segment whereupon relay 26 releases. The opening of the left-hand normal contact of relay 25 opens the energizing circuit for relay 73 which then releases.

Upon the interrupter 66 reaching the next grounded segment, relay 78 reoperates over a circuit extending from battery through the right-hand normal contact of relay 65, junction point 58, Winding ofrelay 7 3. the lower normal contact of relay 37, the left-hand normal contact of relay 35, the right-luind' normal contact of relay 26, the left-hand alternate contact of relay 25, the right-hand normal contact of relay 16, the left-hand alternatecontact of relay .15. the right-hand alternate contact of relay 64, the left-hand normal contact of relay 65 and the interrupter 66 to ground. Relay 36 also operates over a circuit extending from battery through the right-hand contact of relay 65, junction point58 and Winding of relay 36 to the junction point 38 Where it joins the circuit just traced for relay 73. In operating, relay 36 causes the operation of relzu over a circuit extending from battery through the right-hand normal contact of relay 65, the middle alternate contact of relay 36 and the middle normal contact and winding of relay 35 to ground. Relay then locks up through its right-hand alternate contact in the same manner as relays 15 and 25. The opening of the left-hand normal contact of relay causes the release out relay 73. hen relay 35 is energized a locking circuit is estab lished for rela extending from battery through the right-hand normal contact of relay 65, unction point 58, Winding and right-hand alternate contact of relay 36, the left-hand alternate contact of relay 35, righthand normalcontact of relay 26, the lefthand alternate contact of relay the rightnormal contact of relay 16, the lef hand alternate contact'of relay 15., the righthand alternate contact of relay 64, the kit hand normal contact of relay 65, and the interrupter 66 to ground. This locking circuit is maintained until the interrupter 66 reaches a non-grounded segment whereupon relay releases.

When the interrupter 66 engages the next grounded segment, relay 74 operates over a circuit extending from battery through the right-hand normal contact of relay 65, junction point 58, the winding of relay 74, the lower alternate contact of relay 47, the left-hand normal contact of relay 45, the right-hand normal contact of relay 86, the left-hand alternate contact of relay 35, the right-hand normal contact of relay 26, the let'thand alternate contact of relay 25, the right-hand normal contact of relay 16, the left-hand alternate contact of relay 15, the right-hand alternate contact of relay 64, the left-hand normal contact of relay 65, and the interrupter 66 to ground. Relay 46 also operates over a circuit extending from grounded battery, right-hand normal contact of relay 65, junction point 58, the winding of relay 4'6, and the junction point 48 Where itjoins the circuit just traced for relay 74. Energization of relay 46 establishes a circuit for relay 45, extending from battery through the right-hand normal contact o1 relay 65, the middle alternate contact of relay 46, the middle normal contact and Winding of relay to ground. Relay 45 energizes and in so doing opens thepre- Viously described locking circuit for relay 47 through its right-hand normal contact. This locking-circuit is maintained through the left-hand alternate make-before-break contact of relay 46 until relay 46 deenergizes. Relay 45 is locked over a circuit extending from battery through the righthand normal contact of relay 65, junction point 58, and the right-hand alternate contact and Winding of relay 45 to ground. When relay 45 is operated, a locking circuit is established for relay 46 extending from grounded battery, the right-hand normal contact of relay 65, the Winding and righthand alternate contact of relay 46, the lefthand alternate contact of relay 45, the righthand normal contact of relay 36, the lefthand alternate contact of relay 35, the right hand normal contact of relay 26, the lefthand alternate contact of relay 25, the righthand normal contact of relay 16, the lefthand alternate contact of relay 15, the righthand alternate contact of relay 64, the lefthand normal contact of relay and the interrupter 66 to ground. This locking circuit for relay 46 is maintaineduntil a nongrounded segment of the interrupter 66 is reached whereupon said relay releases and permanently opens the locking circuit for relay 47 which also releases. The opening of the left-hand normal contact of relay 45 causes the release of relay 74.

When the interrupter reaches the next grounded segment, relay 7 8 is again operated from the same source of current previously described through the Winding of relay 73, lower normal contact of relay 57, the left-hand normal contact of relay 55, the right-hand normal contact of relay 46, the left-hand alternate contact of relay 45,

' the right-hand normal contact of relay 36,

' pleted from battery I through the left-hand alternate contact of relay 35, the right-hand normal contact of relay 26, the left-hand alternate contact of relay 25, the right-liand normal contact of relay 16, the left-hand alternate contact of relay 15, the right-hand alternate contact of relay 64, the left-hand normal contact of relay and the interrupter 66 to ground. Relay 56 is also energized in a circuit extending from grounded battery, right-hand normal contact of rela 65, junction point 53, winding of relay 56, and the junction point where it joins the circui t just described for relay 73. In energizing, relay 56 establishes circuit for relay 55 extending from grounded battery the right-hand normal contact of relay 65, the middle alternate contact of relay 56, and the middle normal contact and winding of relay 55 to ground. Relay 55, in energizing causes the release of relay 7 3 and locks up in a circuit extending from grounded battery, right-hand normal contact of relay 65, and right-hand alternate contact and winding of relay 55 to ground. The energization of relay 55, also establishes a locking circuit for relay 56 extending from grounded battery righthand normal contact of relay 65, the winding and right-hand alternate contact of relay 56, left-hand alternate contact of relay 55, right-h and normal contact of relay 46, the left-hand alternate contact of relay 45, the right-hand normal contact of relay 36, the left-hand alternate contact of relay'35, the righthand normal contact of relay 26, the lefthand alternate contact of relay 25, the right-hand normal contact of relay 16, the left-hand alternate contact of relay 15, the right-hand alternate contact of relay 64, the left-hand normal contact of relay 65, and the interrupter 66 to ground. This locking circuit for relay 56 is maintained until the interrupter 66 reaches a nongrounded segment whereupon relay 56 releases.

Upon the interrupter 66 reaching the next grounded segment a circuit is comthe winding relay 65, the relay 56, the relay 55, the relay 46, the relay 45, the relay 36, the relay 35, the relay 26, the relay 25, the

and middle normal contact of right-hand normal contact of left-hand alternate contact of right-hand normal contact of left-hand alternate contact of right-hand normal contact or" left-hand alternate contact of right-hand normal contact of left-hand alternate contact of right-hand normal contact of relay 16, the left-hand alternate contact of relay 15, the right-hand alternate contact of relay 64, the left-hand normal contact of relay 65 and the interrupter 66 to ground. Relay 65 is there by operated and is locked during the engagement of the grounded segment of the interrupter 66 over a circuitextending from battery through the winding and right-hand alternate contact of relay 65 and the grounded segment of interrupter 66 to ground. The opening or" the right-hand contact of relay 65 removes the battery from the holding cirbattery 59 across the signaling path extending from office X to oiii ce Y, so that current flows from the P05161176 terminal of battery 59, through the alternate contact of relay 73,

the windings of relay 76 in parallel, resistances 71 and 7 2, the conductor connected to line A extending between ottice X and olfice Y, the windings of relay 170 in series, the low and high resistances 171 and 172, the conductor of the line circuit C extending from office Y to office X to the other side of battery 59. The windings of relay 70 are balanced by the resistances 71 and 72, but the direction of current flowing over this circuit is such that relay 170 closes its upper. contacts thereby establishing a circuit extending from grounded battery, through the left-hand normal contact of relay 192, the windingflof relay 113, the right-hand normal contact of relay 114, the right-hand normal contact of relay 192 and the upper left-hand contact of relay 170 to ground. Relay 113 inoperating over this circuit causes'the operation of relay 114 over a circuit extending from battery through the left-hand contact of relay 192, the righthand alternate contact of relay 113 and the left-hand normal contact and windin of relay 114 to ground. Relay 113 then locks up through its winding andleft-hand alternate contact and the right-hand alternate contact of relay 114. The opening of the right-hand normal contact of relay 114 opens the energizing circuit of relay 113 but this relay remainsin. its locked condition until the termination of the impulse, whereupon it releases. Relay 114 locks over a circuit extending from battery through the left hand normal contact of relay 192 and the left-hand alternate contact and winding of relay 114 to ground. I V V The second impulse of current received through relay 17 O in response'to the second operation of relay 73 completes a circuit extending from battery through the left-hand normal contact of relay 192, the winding of relay 123, the righthand normal contact of relay 124, the left-hand normal contact of relay 113, the right-hand alternate contact of relay 114, the right-hand normal contact of relay 192 and the upper left-hand contact. of relay 170 to ground. Relay 123 thereupon operates and causes the operation of relay 124 over a circuit extending from battery through the left-hand normal contact of relay 192, the right-hand alternate contact of relay 123 and the left-hand normal contact and winding of'relay 124 to ground. The operation, of relay 124 closes a locking circuit for relay 123 extending through the winding and leftdrand alternate contact of said relay and this circuit remains effective throughout the duration of the impulse. Relay 124 is locked. over a circuit extending from battery through the lefthand contact of relay 192 and the left-hand alternate contact and winding of relay 124 to ground.

The third impulse of current sent through relay 170 in response to the third operation of relay 3 completes a circuit extending from battery through the left-hand normal contact of relay 192, the winding of relay 133, the righthand normal contact of relay 134, the left-hand normal contact of relay 123, the right-hand alternate contact or" relay 124, the left-hand normal contact of relay 113, the right-hand alternate contact of relay 114, the right-hand normal contact of relay 192 and the upper left-hand contact of relay 170 to ground. Relays 133 and 134 are energized and locked in the same manner as previously described in connection with other similar relays.

The fourth impulse of current received through relay 170 in response to the operation of relay 74, simultaneously with relay r: 46, is or" such direction from the battery 59 that relay 170 closes its lower contacts. A circuit is now completed which extends from battery through the left-hand normal contact of relay 192, the winding of relay 143, the right-hand normalcontact of relay 144, the left-hand normalcontact of relay 133, the right-hand alternate contact of relay 134, the left-hand normal contact of relay 1.2? the right-hand alternate contact of relay 124, the left-hand normal contact of 113, the right-hand alternate contact of relay 114, the right-hand normal contact of relay 192, the winding of relay 193, and the lower left-hand contact of relay 170 to ground. Relay 143 operates over this circuit. Relay 190 thereupon operates over a circuit extending from battery through the left-hand normal contact of relay 192, the contact of relay 193, the lower normal contact, winding and the upper normal contact of relay 190, the right-hand normal contact of relay 144 where it joins the circuit previously traced for relay 143. operating locks over a circuit extending from battery through the lower alternate contact, the winding and the middlealternate contact of relay 190 and the contact of relay 191 to ground. Relay 143 in operating causes the operation of relay 144 over a circuit extending from battery through Relay 190 in the lefthand contact of relay 192, the righthand alternate contact of relay 143 and the left-hand normal contact and Winding of relay 144 to ground. Relay 143 momentarily locks up through its winding and lefthand alternate contact until the impulse is completed whereupon said relay releases. he relay 144 remains looked over a circuit which extends from battery through the lefthand normal contact of relay 192, the lefthand alternate contact and winding of relay 144 to ground. The operation of relay 190 completes a ground connection for the filament cattery supply circuits of telephone repeaters BA, BB, and RC associated with the line circuits A, B and C respectively, such ground connection being extended through the contact of relay 191 and the upper alternate contact of relay 190.

The fifth impulse of current which is sent over the signaling path and received through the windings of relay 170 due to the operation of relay 7 3 simultaneously with the operation of relay 56 causes relay 170 to again close its upper contacts thereupon establishing a circuit extending from battery through the left-hand normal contact of relay 192, the winding 01"- relay 153, the right-hand normal contact of relay 154, the left-hand normal contact of relay 143, the right-hand alternate contact of relay 144, the lett-hand normal contact of relay 133, the right-hand alternate contact of relay 134, the left-hand normal contact of relay 123, the right-hand alternate contact of relay 124, the left-hand normal contact of relay 113, the right-hand alternate contact of relay 114, the righthand normal contact of relay 192 and the upper left-hand contact of relay 17 0 to ground. Relay 153 in operating causes the operation of relay 154 over a circuit extending from battery through the left-hand normal contact of relay 192, the right-hand alternate contact of relay 153 and the lefthand normal contact of winding of relay 154 to ground. Relay 153 is locked up in a circuit extending through its winding and left-hand alternate contact and the middle alternate contact of relay 154 and remains in this condition throughout the duration of the impulse. Relay 154 is looked over a circuit extending from battery through the left-hand normal contact of relay 192 and the left-hand alternate contact and winding of relay 154'to ground. Upon the cessation of the fifth impulse, relay 192 operates over circuit extending from battery through the winding and middle normal contact of relay 192, the right-hand normal contact of relay 153, the middle alternate contact of relay 154, the normal contact of relay 143, the right-hand alternate contact of relay 144, the normal contact of relay 133, the right-hand alternate contact of relay 134, the normal contact of relay 123, the right- 192, which thereupon returns to normal.

The closure of the upper contact of relay 1-70, in response to the first impulse transvmitted by the operation of relay 73 when plug is inserted in jack 10, also completes a circuit from battery through. the Winding of relay 183' and the right-hand upper con tact of relay 170 to ground. The second, third and fifth impulses transmitted also operate relay 183 over the same circuit, but

the fourth or positive impulse sent operates relay 184 over a circuit extending from battery through the Winding of said relay and the right-hand lower, contact of relay 170 to ground. Upon each energization of relay. 183, battery 159is connected across the line over a circuit extending through the alternate contact of relay 183, the windings of relay 180 in parallel, the resistances 181 and 182, the simplexed conductors of line circuit A extending between office Y and oliice Z, the low and high resistances271 and 272,thje windings of relay 27 0' in series, thesinip'lexed conductors of line circuitCextendingsbetween office Z and oflice Y to the other pole of battery 159. The strength of extending from ground througlrthe Winding and right-hand normal contact thereof, the left-hand alternate contact of relay 213 and the right-hand normal contact of relay 260 to grounded battery. Upon the energization of relay 214 a temporary locking circuit is established for relay 213' which lasts througho 'lt the duration of the impulse, said circuit extending from grounded battery through the right-hand normal contact of relay 260, the; winding and right-hand alternate contact of relay 213, the left hand alternate contact of relay 214, the. left-hand normal contact of relay 260 and the upper contact of relay 270 to ground. Relay 214 locks up through its winding and right-hand alternate contact to grounded battery at the right-hand normal contact of relay 260. At; the tern'iination of the impulse, the locking circuit for relay 213 is opened and said relay releases. The second, third and fifth impulses operate to successively energize relays 223, 224, 233, 234, 253 and 254, in the same man.- ner as described in connection with relays 123, 124, etc. The fourth impulse, which causes the energization of relay 184, estab lishes a circuit extending from positive pole of battery 1 9 overthe simplexed conductors of line circuit A extending from office Y to officeZ, the resistances 271 and 272, the windings of relay 270, the simplexed conductors of line circuit C eXtendingbetween ofiice Z and office Y,'the windings of relay 1'80, associated resistances 1 81 and 182, normal contact of relay 183- and the contact of relay 184. to the other pole of battery. The'strength and direction of flow of the current in this circuithas no efi'ectupon relay 180, the windings thereof being balanced by the resistances 181 and 182, but relay 270 operates to close its lower contact; .A circuit is then established extending from grounded battery, the right-hand normal contact of relay 260, the Winding of'relay normal contact of relay 223, the left-hand alternate contact of relay 224, the normal contact of relay 213, the left-hand alternate Contact of relay 214, the left-hand normal contact ofrelay 260, the Winding of relay 281 and the lower contact of relay 270 to ground; The relays. 243 and 261 I, are ,energized in this circuit but the energization of relay 261 at this time has no effect upon the circuit. The energizationof'relay 243 causes the energization of relay 244 and the establishment ofa locking'circuit therefor, in the same manner as described in connection with relay 214; At the termination of the fifth impulse relay 260 is energized by the circuit extending. from battery through the Winding and middle normal contact of relay 260, the left-hand normal contact'of relay 253, the middle alternate contact of,

relay 254, from thence through contacts of relays-243, 244. 233, 234, 223,224, 213, 214;

normal contact of'relay 253 to ground. v.Re-

lay 260 energizes and causes the release of relays 214, 224, 234, 244 and 254 and then the source of alternating current through the lower alternate contact of key 3, the ring contacts of plug 1 and jack 10, the lower normal contact of relay 12, the upper Winding of relay 1?, the condenser 19, the upper nornial contact of relay 12, the tip contacts of jack 10 and plug 1, and the upper alternate contact of key 3 to ground. Relay 1? energizes and locks in a circuit extencing from ground through its lower Winding and upper alternate contact, the norinal leit hand contact of relay 16, the normal righthand contact of relay 15, the winding of relay 62 and the righthand normal contact relay 65 to grounded battery. Relay 62 en ergizes in this circuit and through the interrupt r 63 establishes a circuit for relay 61, as previousl described, whereupon relay 64 locks up. Upon the energization of relay 64, a circuit is established from grounded battery through the right-hand normal contact of relay 65, junction point 56, the inciing of relay 16, junction point 18, tne left-- hand norinal contact oi relay the righthand alternate contact relay 6%, the lefthand normal contact of relay 65 and a grounded segment of interrupter 66 to ground. At the same th is another circuit is established from the same source of current through the Winding of relay 7 1, the lower alternate contact of relay 1' to the junction point 18 Where it joins the previously described circuit for relay 16. The energizetion of relay 16 initiates another ope ation of the chain or" relays 15, 16, 25 and 26, etc, which is the same in all respects as tae pre vious operation of this chain of relays with the exception that relay '5 is operated upon the first impulse instead of the fourth. V] hen relay 16 releases and rela 15 loclis in this series of operations, the loosing circuit for relay 17 is opened. The energization oi relay 74. connects hatter Y 59 across the line to energize the polarized relay 170, Which first closes its lower contacts and then its upper contacts in response to the successive energizations of relay '73 following the energization of relay 7 1. The energization of relay 1T0 initiates the sane operation, as previously described in conr. ccion with relays 113, 11 i, 123, 124-, etc., but the operation of these relays has no cficct upon the repeater circuits since relay 190 has been energized and locked in the manner previously described. In response to the first energization of relay 1'50 when the same closes its lower contacts, the circuit is established for relay 181-. This connects battery 160 across the signaling circuit whereby relay 270 is energized as previously 0 close its lower contact. Relays 213, 214:, 28, 224, etc, having been released after the Lamination ot the fifth impulse of the first ,eries, a circuit is now establi hed from grounded battery through the right-hand again relays 213, 21 and 261 a circuit is establlshed from grounded Trough the ri ilt-hand n rnial contact oi a 260 the a n a .1 2

contact ofrelay the winding of relay 212, the 1 "-hand alto rte contact of relay hand lljlel'lliltfi contact of relay nand normal contact of mg of relay 261 and the Z0 to ground. Relay 212 energizes and remains in this condition throughout the duration of the impulse. By attracting its arinatures, relay 212 estahlishes a Cll'Clllt n drop or signal 211 e:-: tending from the r alternating curnt through the rnate contact of relay 212, the Winding oi iop 211 and the upper alternate contact of re ay 212 to ground. Drop 211 .pon energizing displays a signal to ndicate to the operator at ofiice Z that a-connection is desired over the line A. The succeeding impulses of the second series initiateo at oliice X operate through the relay 183 to energize relays 223, 224-, 233, 23 1, etc, in the same manner as previously described in connection with these relays, but this operation has no effect upon the circuit. At the end of the impulses, relay 26 again operates as previously described to restore relays 214,-, 22 2 2 1 1 and 254-. In response to the signal isalayed at the operator s position, a plug 201 or" linlr circuit E at ofiice Z is inserted into jack 210, thereby disconnecting the Winding oi drop 211 from the line A and cans. lg the opera-ti n of relays 202 and 267 over a circuit extending from battery through the Winding of relay 202, sleeve contacts or plug 201 and jack 10, and the Winding of relay 26? to ground. 1 response to the operation of relay 267, r ys 268 and '9 is slow to operate, a temporary circuit is stablished for relay 2%? which extends troin ttery through the alternate contact of relay 268, the upper Winding relay 217 and the normal contact of rel y to ground. d lay 2%? in. ope g locks over a circuit extending from at the left-hand normal contact or re. through the windin relay 262, toe eft-hand normal conrelay 2 15, the rignt-hand normal conact of relay and the middle alternate contact, the lower winding and the upper alternate contact of relay 2%? to ground. In operating, re ay 262 prepares a circuit for relay 2641 so that when the interrupter 263 engages the next succeeding grounded seg- 269 operate, and since rela,

ment, re1ay'264 operates over a circuit extending from battery through the righthand normal contact of relay 265, the junction point 258, the winding :tl'lfl normal contact of relay 264, the contact 0-; relay and the grounded segment of relay 263 to ground. "A circuit is also completed extend ing from battery through the right-hand normal contact of relay. 265, the auction point 258, the right-hand normal contact of relay 215, the winding of relay 216, the letthand alternate contactolf relay 264, the right-hand normal contact of relay 265 and upon the engagement oi a grounded segment through theinterrupter 266 to ground. Helays 215, 226, 225, 23c, 246, 250, 2:: and 265 thereupon operate in response to the successive enga ements of the grounded segments of the impulse-sending interrupter 266 in a manner similar to that described for the first series of operations ot elays 16, 15, 26, 25, 36, 35, 46, 45, 56, 55 and 65 at oilice X in initiating a call. The impulses impressed upon the. signaling circuit comprising the simplexed conductors or" the line circuits A and C, extending from oiiice Z to cities Y, in response to the operation of relays 273 and 274 caused by the stepping operation of the ,other relays, causes the operation of polar relay 180 in a manner similar to that described for polar relay 170 in response to the similar series of impulses transmitted from cities X to office Y. However, the modified impulse which is transmitted by the operation of relay 274simultaneously with relay 246, willproduce no other effect upon the system than the usual etiect produced upon the step )ing relays 143 and 144, since the filament attery supply circuits of repeaters R4, R13, and RC are controlled independently of such relays by the locking of relay 190 through the contact of relay 191 in response to the transmission of the signals from oflice'X to ofiice Y. Therefore, relays 113, 114, 123,124, 133, 134, 143, 144, 153, 154 and 192 operate as previously described. The operation of relay 180 also causes the operation of relays 173 and 174 to repeat-the series of impulses into the circuit including simplexed conductors of the line circuits A and C, extending from oflice Y to oflice X, and in response to such impulses i-elay op crates to cause relays 13, 14, 23, 24, 33, 34, 43, 44, 53,, 54, 60 and 61 to operate in a manner similar to that described in connection with the response of relays 213, 214, 223, 224, 233, 234, 243, 24.4, 253, 254, 260 and 261 upon the receipt or the signaling impulses from office X. However, relay 12 does not operate in the manner described for relay 212 in the second series of operations of stepping relays at ofiice Z, since the ringing key 203 in the link circuit E, associated with the line circuit A has not been actuated.

I V V 1,484,983 7 By the actuation of the listening keys 4' and 204 respectively of circuits l) and E, associated with the'hne (J1]'C1ill)'i\,'ttCO1llinunication channel is establishedbetween the operators at said offices for thehne c1r-- unit 1 O mwfor at 07 m X tau-Hiatus a call .o vc-r' p/umtom Zinc circuit B.

'lhc operator at oilice Xdesiring to conrenipora eously extend a call from ol'iice X to otiice Z over phantom circuit 13, inserts plug 1 oi another link circuit 1) at office X into jack 24) of the line circuit l5, thereby c1 ing the operation of relay 2 over a cir- -i it extending from battery through the Winding of ray 2, the sleeve contacts of plug 1 and jac: O whereit joins the cir-- cuit trrued For relay 67 in connection with the initiation of the callover line circuit A. Relay 6? having operated in connection with the previous call no material effect is produced upon the system at this time. The

operator at office X thereupon actuates ringing key associatertwith the selected link circuit D completing a circuit extending from: the source of alternating current through the lower alternate contact. of key 3, the ring contacts of plug 1 and jack 2O, the lower normal contact of relay 22, the upper winding of relay 27, the condenser 29, the upper normal c'ontactof relay 22,

the tip contacts of jack 20 and plug 1 and the upper alternate contact of. 'key 3 to' ground. Relay 2? thereupon, operates, the cpeinngoi the upper and middle normal contacts thereof disconnecting the line terininal from the line circuit extending to the distant otiices, and in closing the upper altern ate contact of relay 27 establishes a loching circuit for itself which extends from battery through the light-hand normalcontact of relay 65, the winding of relay 62, the right-hand normal contact of relay 25, the left-hand normal contact 01" relay 26 and the upper alternate contact and lower winding of relay 27 to ground. The'operation of relay 62, as in the previous instance,

circuit A. The locking circuit for relay 2'?" is opened at the termination ofthe second impulse by the release of relay 26 and continucd energization of relay 25. Relays 73 and 74 respond to this series of operations in a manner similar to that previously described, excepting that relay 74 instead of iii relay 7 3 operates simultaneously with relay 26, thereby causing a reversed current or positive impulse to be transmitted over the circuit including simplexed conductors of line circuits A and C, extending from office X to oilice Y. At ol'lice Y relay 170 responds to such impulses and no efiect is produced upon the apparatus located" at office Y, except the stepping operation of relays 113, iii, 123, 124, 133, 134, 143, 144,, 153, s and the operation of relay 192 to release the locked relays. However, the impulses are repeated by the relay 170 cooperating with relays 183 and 18% into the circuit including the simplexed conductors of line circuits A and C, extending from office Y to office Z, in a manner similar to that previously described, excepting that relay 18 i is operated instead of relay 183 in re sponse to the second impulse which is sent by relay 74. These impulses are received by relay 270 which operates in response to the first impulse to'close a circuit extending from battery through the right-hand contact of relay 260, the winding of relay 213,

the left-hand normal contact of relay 214, the left-hand normal contact of relay 260 and the upper contact of relay 270 to ground. The current flowing through this temporary circuit causes the operation of relay 213, which in turn causes the operation of relay 214 in a manner similar to that described in connection with the call which was extended over line circuit A.

9 However, due to the reversed polarity of the second impulse being transmitted from oliice X through otlice Y, relay 270 in response to such second impulse closes its lower contact thereupon causing the operation of relay 223 in the manner similar to that previously described, but also causes the operaion of relay 261 over a circuit extending from battery through the right-hand contact of relay 260, the winding of relay 223,

the left-hand normal contact of relay 224, the righthand normal contact of relay 213,

the left-hand alternate contact of relay 21 the left-hand normal contact of relay 260, the winding of relay 261 and the lower contact of relay 270 to ground. Relay 261 completes a circuit for causing the operation of relay 222 which extends from battery through the right-hand normal contact or" relay 260, the contact of relay 261 and the winding or relay 222 to the lower right hand alternate contact of relay 223 where it joins tlie circuit previously traced for the latter relay which is locked during the transr ission of the impulse. lheretore, relay 2 is temporarily operated during the transmission of the impulse and completes a circuit extending from the source of alterhating current through the lower alternate contact of relay 222, the lower normal contact of jack 220, the wind ng of signaling device or dropx221, the-uppernormal con tact of jack 220 and the upper alternate contact of relay 222'to ground. Signaling device 221 thereupon operates'indicating tov the operator at office Z. thata call is being extended over the line circuit B. In response to-the display of the signal produced by the-device-221, the'operator at office Z inserts plug: 201' of another link; circuit E Operator at o fi'ce X initiates a call 0031" line circuit 0.

The operator at office X desiring to contemporaneously extend a call over line circuit C, inserts the plug 1 of a third link circuit D- thereat into the jack 30, thereby causing the operation of relay 2 as in the case of the call being extended from the line circuit B. The ringing key 3 of such link circuit B being actuated, a circuit is completed extending from the source of alternating current through the lower alternate contact of ringing key 3 of the selected link circuit D, the ring contacts of plug 1 and jack 30, the lower normal contact of relay 32, the upper winding of relay 37, the condenser 39, the upper normal con. tact or relay 32, the tip contacts of jack and plug 1 and the upper alternate con tact of key 3 to ground. Relay 37 operates in response to the current flowing over such circuit and locks in an operated condition over a circuit extending from battery through the right-hand normal contact of relay 65, the winding of relay 62 the righthand normal contact of relay 35, the lefthand normal contact of relay 36, theupper alternate. contact and lower winding of relay 37 to ground. Relay 37 remains locked throughout the duration of the third impulse. The operation of relay 37 disconnects the line terminal from the line circuit extending to the distant otlices. As in the previous instance, relay 62 operates to include the interrupter 63 in circuit with the relay 64-, so that the impulse-sending interrupter 66 is included in circuit with the relay 16 to cause the sequenceof operations of relays 15, 26, 25, 36, 35, i6, 45, 56, and as previously described, such sequence of operations causing the operations of relays 73 and 74 as described in connection with the initiation of the call over line circuit A, except that on the third impulse relay 3 74 instead of relay 73 operates siniultane- ENG) versed current impulse to be transmitted over the signaling circuit including the simplexed conductors of line circuits A and C, extending from otfice X to office Y. These impulses being received at office Y produce no material effect thereat, and are repeated in a manner similar to that previously described to the signaling circuit including the simplexed conductors of line circuits A and 0, extending from oflice Y to o'liice Z. Upon the receipt of these impulses at office Z, relay 270 operates, as described in connection with the receipt of the call from oflice X, over line circuit A, except that in response to the third impulse such relay closes its lower contact so that although relays 213, 214, 223, 224, 233, 234, 243, 24-1, 253, 254 and 260 operate as previously described in connection with the first series of impulses received in connection with the initiation of the call over the line circuit A, when the third impulse is reached in the series, relay 261 operates over a circuit extending from battery through the righthand normal contactof relay 260, the wind-- ing of relay 233, the left-hand normal contact of relay 234, the right-hand normal contact of relay 223, the left-hand alternate contact of relay 224, the right-hand normal contact of relay 213, the left-hand alternate contact of relay 214, the left-hand normal contact of relay 260, winding of relay 261, and the lower contact of relay 270 to ground. In response to the operation of relay 261, relay 232 is momentarily operated over a circuit extending from battery through the right-hand normal contact of relay 260, the contact of relay 261, the winding of relay 232 to'the lower right-hand alternate contact of relay 233 where it joins the operating circuit of relay 233. The operation of relay 232 establishes a temporary circuit which extends from a source of alternating current through the lower alternate contact of relay 232, the lower normal contact of jack 230,. the Winding of signaling device 231, the upper normal contact of jack 230 and the upper alternate contact of relay 232 to ground. Relays 243, 244, 253, 254 and 260 thereupon operate as in the previous instances. In response to the signal displayed by the device 231, the operator at oiiice Z inserts the plug 201 of another link circuit E at office Z into jack 230, thereby removing the winding of the line signaling device 231 from connection with the line and caus ing the operation of relay 202 in the con nected link circuit as in the previous cases.

Operator at ofiice Z transmits disconnect signals to operator at ofice X.

Upon the completion of the conversation over line circuit A, the operator at oifice Z actuates ringing key 203 of the link circuit E thereat, causing the operation of ringing response relay 217 over a circuit extending from a source of alternating current through the lower alternate contact of key 203, the ring contacts of plug 201 and jack 210, the lower normal contact of relay 212, the upper winding of relay 217, the condenser 219, the upper normal contact of relay 212, the tip contacts of jack 210 and plug 201 and the upper alternate contact of key 203 to ground. In operating, relay 217 disconnects the conductors leadin to the tip and ring contacts of the jack rrom the outgoing line conductors and looks over a circuit extending from battery through the left-hand normal contact of relay 265, ind ing of relay 262, the left-hand normal contact of relay 215, the right-hand normal contact o1 relay 216 and the upper alternate contact and lower winding or relay 217 to ground. in operating, relay 262 prepares a circuitincluding the interrupter 263 in circuit with the winding of relay 264 so that when a grounded segment o1 the interrupter is reached, relay 264 operates over a circuit extending from grounded battery, through the left-hand normal contact of relay 265,

the winding and normal contact of relay 264, the contact of relay 262, and the interrupter 263 to ground. In operating, relay" 264 locks over a circuit extending from grounded battery, through the left-hand. normal contact of relay 265, winding and right-hand alternate contact of relay 264 to ground. A. circuit is thereupon prepared including the impulse sending interrupter 266 in circuit with the various stepping relays so that when the first grounded segment of interrupter 266 is reached, relay 274 operates over a circuit extending from grounded battery, left-hand normal contact of relay 265, junction point 253, winding of relay 274, lower alternate contact of relay 217, right-hand normal contact of relay 215, left-hand alternate contact of relay 264, right-hand normal contact of relay 265, and the interrupter 266 to ground. A circuit is simultaneously established for relay 216, 7

extending from grounded battery, left-hand normal. contact of relay 265, junction point 258, winding of relay 216 and the junction point 218 where it joins the circuit previously traced for relay 274. Relay 216 energizes and establishes a circuit for relay 215,

Relay 215 energizes and escircuit extending from grounded battery through the left-hand normal contact of relay 265, left-hand alternate Contact and Winding of relay 215 to ground. When the interrupter 266 disengages the grounded segment, relay 216 releases but relay 215 remains locked in an operated condition over the circuit just traced therefor. Relay 2741 releases upon the release of relay 216 but during the period in which relay 27 1 is operated, a circuit is completed from one pole of battery 269 through the alternate contact of relay 27 1, the normal contact of relay 273, the windings of relay 270 in parallel, the simplexed conductors or" line circuit C'extending from otlice Z to office Y, the windings of relay 180 in series, the simpleXed conductors connected to line circuit A extending from office Y to ofiice Z, and to the other side of the battery 269. The low and high resistances 271 and 272 in this circuit balance the windings of relay 276 and this relay, trlQIQfOI'Q, does not operate but the circuit passing through the windings of relay 180 in series, is unbalanced by the resistances 181 and 182, and relay 180, therefore, operates to close its lower contacts. Upon the release of relay 216, relay 217 releases to complete the continuity of the line conductors and relay 226 thereupon operates when the innoulsesending interrupter 266 reaches the next grounded segment, the circuit for such relay being traceable from battery through the left-hand normal contact of relay 265, the winding of relay 226, the right-hand normal contact of relay 225, the left-hand normal contact of relay 216, the right-hand alternate contact of relay 215, the left-hand alternate contact of relay 26 1, the right-hand normal contact of relay 265 and the interrupter 266 to ground. Relay 273 also operates at this time over a circuit extending from battery through the le t'thand normal contact of relay 265, the winding of relay 273, the lower normal contact of relay 22. to the righthand normal contact ct relay 225 where it joins the circuit just traced for relay 226. The operation or relay 273 connects battery 259 across; the signaling circuit extending from o'liice Z to office Y, thereby providing the reversed direction of current flowing in such signaling circuit. Relay 226 in operating cau.;es the operation of relay 225 over a circuit extending from battery through the left-hand normal contact of relay 265, the middle alternate contact oi": relay 226 and the middle normal contact and winding of relay to ground. Relay 225 then locks in a circuit through its winding and left-hand alternate contact. Relay 226 thereupon locks over a circuit extending from battery through the left-hand normal contact of relay 265. the Winding and letthand alternate contact of relay 226, the righthand ,lternate contact of a relay 225, the left-hand normal contact of relay 216,

Ki l.

the right-hand alternate contact of relay 215, the left-hand alternate contact of relay 264-, the right-hand normal contact of relay 265 and the interrupter 266 to ground. l hen the interrupter disengages the grounded segment, relay 226 is released, and when relay 225 operates, relay 273 is released, but relay 225 remains locked.

Relay 236 operates when the interrupter 266 engages the next grounded segment, the operating circuit for such relay being established from battery through the left-hand normal contact of relay 265, the winding of relay 236, the right-hand normal contact 01" 1 lay 235, the left-hand normal contact of relay 226, the right-hand alternate contact of relay 225, the left-hand normal contact oi relay 216, the right-hand alternate contact of relay 215, the left-hand alternate contact of relay 26 1-, the right-hand normal contact of relay 265 and the interrupter 266 to ground. Relay 273 also operates over a circuit extending from battery through the left-hand normal contact of relay 265, the windings of relay 273, the lower normal contact or relay 237 and the right-hand normal contact of relay 235 where it joins the circuit trac d for relay 236. Belay 235 thereupon operates over a circuit established from battery through the lefthand normal contact of relay 265, the middle alternate contact of relay 236 and the middle normal contac and winding of relay 235 to grouiul. Relay 235 in operating looks over a circuit extending 'om battery through the left-hand normal contact of relay 265, and the left-hand alternate contact and winding of relay 235 to ground. Relay 236 thereupon looks over a circuit extending from battery through the left-hand normal contact ot relay 265, the winding and left-hand alternate contact of relay 236, the righthand alternate contact ot relay 235, the lefthand normal contact of relay 226, the righthand alternate contact of relay 225, the lefthand normal contact of relay 216, the righthand alternate contact of: relay 215, the left-- hand alternate contact of relay 264, the right-hand normal contact of relay 265 and the interrupter 266 to ground. The opera tion of relay 235 releases relay 273, removing battery "from the signaling circuit extending from ofiice Z to office Y, and when the impulse-sending interrupter 266 disengages the grounded segment thereof, relay 236 is released but relay remains looked over a circuit traced therefor,

Atelay 246 then operates when interrupter 266 engages its next grounded segment over circuit extending from battery through the left-hand normal contact or the winding of re y 246, the right-hand normal contact of relay 24:5, the left-hand normal contact of relay the righthand alternate contact of relay 235, the left-hand alternate contact of relay 264, the righthand normal contact of relay 265, and the interrupter 266 to ground. Relay 273 again operates, the circuit therefor being traced from battery through the left-hand normal contact of relay 265, the Winding of relay 273, the lower normal contact of relay 247 to the right-hand normal contact of re lay 245 Where it oins the circuit traced for relay 246. 111 operating, relay 246 causes the operationof relay 245 over a circuit extending from battery through the left-hand normal contact of relay 265, the middle al ternate contact of relay 246 and the middle normal contact and Winding of relay 245 to ground. Relay 245 looks over a circuit extending from battery through the left-hand normal contact of relay 265 and the letthand alternate contact and Winding of relay 245 to ground. The opening of the righthand normal contact of relay 245 causes the release of relay 273, thereby removing the battery 259 from operative association With the signaling circuit extending from oliice Z to oihce Y. Upon the disengagement of the grounded segment of interrupter 266, relay 246 is released but relay 245 remains looked over a circuit traced for that purpose.

When the interrupter 266 engages the next grounded segment thereof, relay 256 is operated over a circuit extending from battery through the left-hand normal contact 01" re lay 265, the Winding of relay 256, the righthand normal contact of relay 255, the lefthand normal contact of relay 246, the righthand alternate contact of relay 245, the lefthand normal contact of relay 236, the righthand alternate contact of relay 235, the lefthand normal contact of relay 226, the righthand alternate contactot relay 225, the lefthand normal contact of relay 216, the righthand alternate contact of relay 215, the lefthand alternate contact of relay 264, thev tending from battery through the left-hand normal contact of relay 265, the middle alternate contact of relay 256 and the middle normal contact and Winding of relay 255 to ground. Relay 255 thereupon looks over a circuit extending from battery through the left-hand normal contact of relay 265 and the left-hand alternate contact and Winding of relay 255 to ground. Relay 256 also looks over a circuit extending from battery through the left-hand normal contact of relay 265, the Winding and left-hand alternate contact of relay 256, the right-hand alternate contact of relay 255, the left-hand normal contact of relay 246, the right-hand alternate contact of relay 245, the left-hand normal contact of relay 236, the right-hand alternate contact of relay 235, the left-hand normal contact of relay 226, the right-hand alternate contact of relay 225, the left hand normal contact of relay 216, the right-hand alternate contact of relay 215, the left-hand alternate contact of relay 264, the righthand normal contact of relay 265 and the interrupter 266 to ground. Relay 273 releases uponthe operation of relay 255 and relay 256 releases When the grounded segment of interrupter 266 is disengaged. 110W:

ever, relay 255 remains in an operated condition over a locking circuit traced therefor.

When the interrupter engages the next grounded segment a circuit is completed extending from battery through the Winding and middle normal contact of relay 265, the

left-hand normal contact of relay 256, theright-hand alternate contact of relay 255, the lett-hand normal contact of relay 246, the right-hand alternate contact of relay 245, the lefthand normal'ccontact of relay 236, the right-hand alternate contact of relay 235, the left-hand normal'contact of relay 226, the right-hand alternate Contact of relay 225, the left-hand normal contact of relay 216, the right-hand'alternate contact of relay 215, the left-hand alternate contact of relay 264, the right-hand normal contact of relay 265 and the interrupter 266 to ground. Relay 265 operates over the circuit just traced and locks'during the continued engagement of the grounded segment of the interrupter 266 over a circuit extending from battery through the Winding and left-hand alternate contact of relay 265 and the interrupter 266 to ground. The opening of the left-hand normal contact of relay 265 removes the battery from connection with the locking circuits for relays 215, 225, 235, 245, 255 and 264, While the opening of the right-hand normal contact of relay 265 removes the interrupter from association ith the operating circuits of stepping relays 216, 226, 236, 246 and 256. The locking relays thereupon release and relay 262 also releases due to the removal of the grounded connection from the operating circuit thereof. v

The various impulses thus transmitted over the signaling circuit from office Z to oiiice Y, cause the operation of relayv 180 in a manner similar to that described in connection with relay 170 upon the receipt of'the originating signals from office X, so that the signaling impulses are repeated through the oflice Ycausing the operation of relays 17 3 and 174 in a manner to correspond to the relays and 274 respectively at oflice Z.

The operation of relay 180 in response to the receiptof signaling impulses also causes the series of operations of relays 113, 114, 123, 124,133, 134, 143. 144, 153, 154 and 192111 a manner similar to that described in the transmission of the calling signals from oflice X. The operation of the relays 173 and 174 selectively connect the batteries 159 and 169 with the signaling circuit extending from otlice Y to ofiice X to cause corresponding responses of the polar relay at otlice X. In response to the first operation of relay 70 a circuit is completed from battery through the left-hand normal contact of relay 60, the winding of relay 13, the righthand normal contact of relay 14, the righthand normal contact of relay 60, the wind ing of relay 61, and the lower contact of relay 70 to ground. Relays 13 and 14 are energized and locked in the same manner as described in connection with relays 213 and 214. Relay 61 in operating in this circuit causes the operation of relay 12 over a circuit extending from battery through the left-hand normal contact of relay G0, the contact of relay 61, the winding of relay 12, the lower left-hand alternate contact of relay 13, and the righthand alternate contact of relay 14 where it joins the circuit previously traced for relay 13. Therefore, during the continuation of the first signaling impulse, relay 12 remains operated completing a circuit extending from the source of alternating current through the lower alternate contact of relay 12, the ring contacts of jacks 10 and plug 1. the lower normal contact of key 3 of the link circuit associated with line A at otlice X, the left-hand winding of relay 6, the condenser 7. the upper normal contact of key 3, the tip contacts of plug 1 and jack 10 and the upper alternate contact of relay 12 to ground. Relay 6 in operating in response to the current flowing over this circuit causes the lighting of supervisory lamp 5 over a circuit extending from battery through the contact of relay 2, the local normal contact of key 4, the lower contact of relay 6 and the lamp 5 to ground. Relay 6 also locks over a circuit extending from battery through the contact of relay 2, the local normal contact of key 4 and the upper contact and right-hand winding of relay 6 to ground. Upon the cessation of the impulse, relays 12 and 61 release. Upon the receipt of the next succeeding impulse, relay 7O closes its upper contact and a circuit is completed extending from battery through the left-hand normal contact of relay 60, the winding of relay 23, the right-hand normal contact of relay 24. the left-hand normal contact of relay 13, the right-hand alternate contact of relay 14, the right-hand normal contact of relay 60 and the upper contact of relay 70 to ground. Relay 23 in operating causes the operation of relay 24 over a circuit extending from battery through the left-hand normal contact of relay 60, the right-hand alternate contact of relay 23 and 'he left-hand normal contact and winding of relay 24 to ground. Relay 24 locks over a circuit extending from battery through the left-hand normal contact of relay 60 and the left-hand alternate contact and winding of relay 24 to ground. Relay 23 also locks through its winding and left alternate contact and releases upon the cessation of the impulse but relay 24 remains looked over the circuit described therefor. The third impulse being of the same polarity as that of the second causes relay 70 to close its upper contact completing a circuit from battery through the left-hand normal contact of relay 60, the winding of relay 33, the righthand normal contact of relay34, the left-hand normal contact of relay 23. the right-hand alternate contact of relay 24, the left-hand normal contact of relay 13, the right-hand alternate contact of relay 14, the right-hand normal contact of relay 60 and the upper contact of relay 70 to ground. Relay 34 thereupon operates over a circuit extending from battery through the left-hand normal contact of relay 60, the right-hand alternate contact of relay 33 and the left-hand normal contact and winding of relay 34 to ground. Upon the cessation of this impulse relays 70 and 33 release but relay 34 remains locked independently thereof. The fourth impulse being of the same polarity as of the third causes relay 70 to again close its upper contact to complete a circuit from battery through the left-hand normal contact of relay 60. the winding of relay 43, the righthand normal. contact of relay 44, the lefthand normal contact of relay 33, the righthand alternate contact of relay 34. the left hand normal contact of relay 23, the righthand alternate contact of relay 23, the left hand normal contact of relay 13, the righthand alternate contact of relay 14, the righthand normal contact of relay 60 and the upper contact of relay 70 to ground. Relay 443thcn operates over a circuit extending from battery through the left-hand normal contact of relay 60, the right-hand alternate contact of relay 43. and the left-h and normal contact and winding of relay 44 to ground. Relay 44 then locks over a circuit extending from battery through the lefthand normal contact of relay 60 and the left-hand alternate contact and winding of relay 44 to ground. Relay 43 releases upon the release of relay 70 following ,the cessation of the impulse but relay 44 remains locked over the circuit traced therefor. The fifth impulse being of the same polarity as the preceding one causes relay 70 to again close its 1 ground.

upper contact and to' complete a circuit; from battery through the left-handnormal contact of relay 60, the Winding of relay 53, the right-hand normal contact of relay 54, the left-hand normal contact of relay 43, the right-hand alternate contact of relay 44, the left-hand normal contact of relay 33, the right-hand alternate contact of relay 34, the left-hand normal contact of relay 23, the right-hand alternate contact of relay 24, the left hand normal contact of relay 13, the right-hand alternate contact of relay 14, the right-hand normal contact of relay 60 and the upper contact of relay 70 to ground. Relay 54 thereupon operates over a circuit extending from battery through a the left hand normal contact of relay 60, the righthand alternate contact of relay 53' and the left-hand normal contact and Winding of relay 54 to ground. Relay 54 thereupon locks over a circuit Which may be traced from battery through the left-hand normal contact of relay 60 and the left-hand alternate'contact and Winding of relay 54 to Relay 53 is locked but upon the cessation of the impulse it releases. Relay 54 remains locked independently thereof. Upon the release of relay 53 a circuit is completed from battery through the Winding and middle normal contact of relay 60, the right-hand normal contact of relay 53, the middle alternate contact of relay 54, the normal contact of relay 43, the right-hand alternate contact of relay 44, the normal contact of relay 33, the right-hand alternate contact of relay 34, the normal contact of relay 23,

the right-hand alternate contact of relay contact of relay prevents the reoperation of relay 53, so that upon the cessation of the impulses the receiving apparatus associated with the line circuits A, B and C at oflice X returns to normal.

I In a similar manner upon the completion of the conversation over line (arcuit' B, the operator at ofiice Z actuates ringing key 203 of the link circuit E associated with the line circuit B at oiflce Z. r A circuit is thereby completed extending from the source of alternating current through the lower alternate contact of ringing key 203, the ring contacts of plug 201 and jack 220, the lower normal contact of relay 222, the upper Winding of relay 227, the condenser 229 and the upper normal contact of relay 222 to ground. Relay 227 operates in response to the current flowing through this circuit and looks over a circuit extending from battery through the Winding of relay 262, the lefthand normal contact of relay 225, tl1e righthand normal contact of relay 226 and the upper alternate contact and lower Winding of relay 227 to ground. The ringing key is again released by the operator and relay 262 operates to prepare a circuit for relay 264 so that When the continuously rotating pickup interrupter 263 reaches the nextgrounded segment thereof, relay 264 operates over a circuit extending from battery through the left-hand contact of relay 265, the Winding and the right-hand normal contact of relay 264, the contact of relay 262 and the interrupter 263 to ground. Relay 264 in operating looks over the circuit reviously traced therefor including the rig it-hand alternate contact thereof, so that When impulse-sending interrupter 266 reaches the next grounded segment, relays 273 and 216 operate over circuits traced therefor in connection With the transmission of the disconnect signal over line circuit A, and initiate the series of operations of relays 215, 226, 225, 236, 235, 246, 245, 256, 255 and 265 as described in connection With the previous instance with the exception that relay 274 instead of relay 273 operates simultaneously With relay'226, so that the second impulse transmitted over the signaling circuit from office Z to oflice Y is of the opposite polarity as compared With that transmitted in connection with the disconnect signaling impulse for line circuit A. Relay 227 releases in the same manner as relay 217 to reestablish the continuity of the line conductors. As in the previous instance the operation of relay 265 causes the release of the locked relays as Well as the release of relays 264 and 262. These impulses are received at oflice Y and cause op erations of relay 180 thereat to initiate the usual stepping operations of relays 113, 114, 123, 124,, 133, 134,143, 144,. 153, 154 and the operation of relay 192 which releases the locked relays of the previously mentioned set in the same manner as described in the previous instance. The impulses are also repeated through the agency of relay 180 as it controls relays 173 and 174 so that similar impulses are impressed upon the signaling circuit extending from office Y to ofiice X Where they are received by relay 7 O. The operation. of relay in response to these impulses causes the operations of relays 13, 14, 22, 61, 23, 24, 33, 34, 43, 44, 53, 54, and 60, the operation of the latter relay, as in the other case, unlocking the relays Which have been previously locked. However, relays 61 and 12 do not respond upon the first impulse received, but relays 61 and 22'respond upon the second impulse due to the reversed polarity of such impulse, so that relay 61 operates over a circuit extending from bat- 

